原位产生的SO42-配位的二维无机钴配合物K2[Co3(OH)2(SO4)3(H2O)2]的水热合成及晶体结构

相同的水热反应条件下4-氨基-二(2-吡啶基)-1,2,4-三氮唑(abpt)、KSCN与钴盐(CoCl2·6H2O)反应合成了2种新的钴配合物:零维的单核配合物[CoSCN(abpt)](1α)和二维的无机层状配合物K2[Co3(OH)2(SO4)3(H2O)2](1β),并通过元素分析和红外光谱对其进行了表征.配合物1α的晶体属于单斜晶系,P21/c空间群.配合物1β晶体属于正交晶系,Cmc21空间群.在配合物1α中,abpt和SCN-配体都参与配位与Co(Ⅱ)离子形成了2个不同的单核单元,这些单核单元又通过S原子和N原子之间的氢键作用连成了三维超分子结构;在配合物1β中,abpt配体没有参与配位,而SCN-配体则被氧化成了SO42-离子并与Co(Ⅱ)离子配位形成了二维配位层状结构,相邻层之间进一步通过氢键作用形成了沿c轴方向有孔道的三维超分子网络,这些孔道里面填充着反离子K+.     

X-ray studies of lanthanide(III) complexes with 4-hydroxy-3-methoxybenzoate anion

Polycrystalline complexes of lanthanide(III) with 4-hydroxy-3-methoxybenzoic acid were obtained as hydrated compounds of general formula Ln(C₈H₇O₄)₃?·?nH₂O. After slow recrystallization we obtained single crystals of complexes and determined their structures. Praseodymium(III) and neodymium(III) form isostructural dihydrated complexes [Ln(C₈H₇O₄)₃(H₂O)₂], which crystallize in the triclinic system, space group P 1. Sm(III), Eu(III), Gd(III), Ho(III) and Tb(III) compounds are hexahydrates and also crystallize in the triclinic system, space group P 1. Dihydrated compounds form polymeric chains with metal centres linked by oxygen atoms of bridging carboxylates. Each metal ion is coordinated by chelating carboxylic group and two water molecules. Complexes of the second isostructural group form dinuclear units [Ln₂(C₈H₇O₄)₆(H₂O)₄]?·?8H₂O. Lanthanide(III) ions are linked by oxygen atoms of two chelating–bridging carboxylate groups. In the dimeric structure each metal ion coordinates additionally two chelating carboxylic groups and two water molecules.     

DNA interaction and cytotoxicity studies of ruthenium(III) complexes containing 3-(benzothiazol-2-yliminomethyl)-naphthalen-2-ol ligand

A new Schiff base, 3-(benzothiazol-2-yliminomethyl)-naphthalen-2-ol, has been synthesized and characterized by elemental analysis, Fourier transform infrared spectroscopy (FT-IR), UV–vis, nuclear magnetic resonance, and single-crystal X-ray diffraction. Ruthenium(III) complexes of the Schiff base were synthesized and characterized by analytical and spectroscopic (FT-IR, UV–vis, and electron paramagnetic resonance) data as well as magnetic susceptibility measurements. DNA-binding properties of the ligand and its ruthenium(III) complexes have been investigated by electronic absorption spectroscopy. The three ruthenium(III) complexes were tested for DNA cleavage. Further in vitro study of the cytotoxity of the ligand and the complexes on human cervical cancer cell line and human laryngeal epithelial carcinoma cell line were carried out.     

The Synthesis and Fungicidal Activities of 2,6-Bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]pyridines

In search of better bioactive compounds, a series of novel 2,6-bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]pyridines 2 were synthesized in high yields by the cyclization of 3-aryl-4-amino-5-mercapto-1, 2, 4-triazoles 1 with 2,6-pyridine dicarboxylic acid. 2 exhibited good fungicidal activities against Cerospora beticola sacc.     

Heteroannulated Quinazoline and Quinazolinone Derivatives from (Z)-2-[1-Benzamido-2-(3,4,5-trimethoxyphenyl)]vinyl-3,1-benzoxazin-4(3H)-one

The title compound 1 was prepared and allowed to react with a series of nitrogen nucleophiles to afford the quinazoline and quinazolinone derivatives 2–12 and tetrazole derivative 13. The IR, ¹H NMR, ¹³C NMR, and mass spectra of all the synthesized compounds were discussed.     

Organosoluble and light-colored fluorinated polyimides based on 9,9-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]fluorene and aromatic dianhydrides

A novel fluorinated diamine monomer, 9,9-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]fluorene (II) was prepared via the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride with 9,9-bis(4-hydroxyphenyl)fluorene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides V were synthesized from diamine II and various aromatic dianhydrides III _a-f via thermal imidization. These polymers had inherent viscosities ranging from 0.84 to 1.03 dL/g and were soluble in a variety of organic solvents such as NMP, DMAc, DMF, and DMSO, and some could even be dissolved in less polar solvents such as m-cresol, pyridine, and dioxane. Polyimide films V _a-f had tensile strengths of 85–105 MPa, elongations to break of 7–9%, and initial moduli of 2.13–2.42 GPa. The glass transition temperature of these polymers were in the range of 277–331 °C, their 10% weight loss temperatures were in the range of 539–594 °C in nitrogen and above 544 °C in air, and their char yields at 800 °C in nitrogen ranged between 55–65 wt%. Compared with nonfluorinated polyimides VI, V showed better solubility and lower color intensity. Low dielectric constants (2.68–2.85 at 1 MHz) and low moisture absorptions (0.12–0.24 wt%) were also observed. In particular, V _c-f afforded lightly-colored films, which had cutoff wavelengths lower than 385 nm and b* values ranging from 6 to 22.     

Syntheses,topological networks and properties of four complexes based on 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole ligand

Reactions of metal acetates with 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole (3-abpt) and co-ligands gave rise to four new complexes, namely [Zn₂(3-abpt)(beta)(DMF) (H₂O)₂]_n·nH₂O (1), [Zn(3-abpt)(ip)]_n·3nH₂O (2), [Zn(3-abpt)(ip)(H₂O)₂]_n·2nH₂O (3), and [Cu₂(3-abpt)₂(C₆H₅COO)₄(H₂O)₂]_n·2nH₂O (4) (ip = isophthalate, beta = 1,2,4,5-benzenetetracarboxylate). Compound 1 is a 3D coordination polymer with uncommon 3,4-connected (6².8)₂(6².8².10²) network. Compounds 2–4 are all 1D coordination polymers, which exhibit diversity structures. Compound 2 is a tubular-like chain, 3 is a ring-like network, and 4 is a zigzag chain. Their thermal stabilities and the photoluminescence of 1 have also been investigated.     

Syntheses and characterization of the samarium(III)-copper(II) 3D coordination network constructed by iminodiacetic acid

The hydrothermal reaction of Sm₂O₃ with iminodiacetic acid (H₂Idad), CuO, and H₂O with a mole ratio of 1:2:4:300 resulted in the formation of one nanoporous 3D open framework Cu(II)-Sm(III) coordination polymer, [{Sm₂Cu₃(Idad)₆}·8H₂O]_n. Investigation shows that the coordination polymer possesses high thermal and structural stability. Temperature-dependent magnetic susceptibilities of the coordination polymer with the similar structure, [{Gd₂Cu₃(Idad)₆}·8H₂O]_n, were studied.     

Modelling the use of lanthanides(III) as probes at calcium(II) binding sites in biological systems: Preparation and characterization of neodymium(III) and calcium(II) malonamato(-1) complexes

A bioinorganic approach into the problem of the isomorphous substitution of calcium(II) by lanthanide(III) ions in biological systems is discussed. Reactions of malonamic acid (H₂malm) with Ca^II and Nd^III sources under similar conditions yielded the compounds [Ca(Hmalm)₂]_n (1), [Nd(Hmalm)₂(H₂O)₂]_n(NO₃)_n (2) and [Nd(Hmalm)₂(H₂O)₂]_nCl_n·2nH₂O (3·2nH₂O). Their X-ray crystal structure data show that the malonamate(-1) ligand presents two different ligation modes and coordinates through the two carboxylate and the amide-O atoms, thus bridging three Ca^II ions in 1 and two Nd^III ions in 2 and 3·2nH₂O. Complex 1 is a 3D coordination polymer based on neutral repeating units, whereas 2 and 3·2nH₂O are 1D coordination polymers based on the same cationic repeating unit. Hydrogen bonding interactions further stabilize the 3D framework structure of 1 and assemble the 1D chains of 2 and 3·2nH₂O into 3D networks. The three complexes were characterized spectroscopically (IR, far-IR, and Raman) and the thermal decomposition of 2 and 3·2nH₂O was monitored by TG/DTA and TG/DTG measurements. Variable-temperature magnetic susceptibility data for 2 are also reported. The bioinorganic chemistry relevance of our results is discussed.     

1D & 2D Supramolecular assemblies dominated by crystal structure of Pb(II) oxoanion ( and ) complexes with 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine (PDPT)

The two lead(II) complexes, [Pb(PDPT)(NO₃)₂] _n and [Pb(PDPT)₂(ClO₄)₂EtOH]·CH₃OH, PDPT?=?3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine, have been synthesized and characterized. 1D & 2D supramolecular assemblies of these compounds in the solid state are discussed via covalent and noncovalent donor?···?acceptor interactions.     

Cloud point extraction of lanthanide(III) ions via use of Triton X-100 without and with water-soluble calixarenes as added chelating agents

The use of water-soluble calixarenes: p-sulfonato thiacalixarene (ST), tetra-sulfonatomethylated calix[4]resorcinarene (SR), calix[4]resorcinarene phosphonic acid (PhR) as chelating agents in cloud point extraction (CPE) of La(III), Gd(III) and Yb(III) ions using Triton X-100 as non-ionic surfactant is introduced. The data obtained indicate that both complexation ability and structure of calixarenes govern the extraction efficiency of lanthanides. In particular ST and SR, forming 1:1 lanthanide complexes with similar stability in aqueous media, exhibit different extractability when used as chelating agents in CPE. First synthesized PhR was found to be the most efficient chelating agent exhibiting pH-dependent selectivity within La(III), Gd(III) and Yb(III) in CPE.     

Novel 3d-metal complexes with 1,2-diamino-3-(2-benzothiazolyl)-4(5H)-ketopyrrole: Synthesis,spectroscopic and structural investigations

A series of new 3d-metal complexes have been prepared by the reaction of M(CH₃COO)₂ (M = Zn(II), Co(II), Ni(II)) and 1,2-diamino-3-(2-benzothiazolyl)-4(5H)-ketopyrrole (HL) in a methanol (3) or a methanol/dmf (1, 2) medium. All the complexes have been studied by elemental analyses, electronic and IR spectroscopies. The zinc(II) complex 1 and the ligand HL have been investigated using the method of ¹H NMR-spectroscopy at various temperatures. The disappearance of the signal from one proton of the amino group H(5) in the spectrum of complex 1 confirmed the existence of the ligand in the deprotonated form. According to the data of the ¹H NMR-spectroscopy, the ligand HL is coordinated to zinc(II) through the nitrogen atom of the deprotonated amino group and the nitrogen atom of the benzothiazole substituent. These data are in agreement with X-ray structural studies for the ligand HL and the zinc(II) complex 1.     

Preparation of 3-Aryl-4-(5-ARYL-Δ2-1,2,4-Oxadiazolin-3-YL)Sydnones and their Conversion into 3-ARYL-4-(5-ARYL-1,2,4-Oxadiazol-3-YL)Sydnones

3-Aryl-4-(5-aryl-Δ²-1,2,4-oxadiazolin-3-yl)sydnones (5) were synthesized in high yields by the reaction of 3-arylsydnone-4-carboxamide oximes (prepared from the corresponding 3-arylsydnone-4-carbonitriles) with aromatic aldehydes in the presence of acid catalysts. No reaction occurred when aliphatic aldehydes were used. The oxadiazolin-3-ylsydnones (5) were easily converted into the corresponding 3-aryl-4-(5-aryl-1,2,4-oxadiazol-3-yl)sydnones by N-bromosuccinimide oxidation. The 3-arylsydnone-4-carbonitrile oxides were synthesized in good yields by N-bromosuccinimide oxidation of the corresponding 3-arylsydnone-4-carboxaldehyde oximes.     

Transition Metal Complexes with Pyrazole-based Ligands. Part 8. Characterization and thermal decomposition of zinc(II) complexes with di- and trisubstituted pyrazoles

We report the synthesis and the characterization (elemental analysis, FT-IR spectroscopy, thermal methods and molar conductivity measurements) of the mixed complexes of zinc with acetate and 3-amino-5-methylpyrazole, HL ¹, [Zn(OAc)₂(HL¹)₂], or 3-amino-5-phenylpyrazole, HL ² [Zn(OAc)₂(HL²)₂], or 4-acetyl-3-amino-5-methylpyrazole, HL ³, [Zn(OAc)(L³)(HL³)]₂, with isothiocyanate and HL ² [Zn(SCN)₂(HL²)₂], or HL ³ [Zn(SCN)₂(HL³)₂], and with nitrate, isothiocyanate and 3,5-dimethyl-1-carboxamidinepyrazole, HL ⁴ [Zn(NO₃)(NCS)(HL⁴)₂]. The thermal decomposition of the complexes is generally continuous resulting zinc oxide as end product,except [Zn(OAc)(L³)(HL³)]₂ in which case a well-defined intermediate was observed between 570–620 K. On the basis of the IR spectra and elemental analysis data of the intermediate a decomposition scheme is proposed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis,characterizations and crystal structures of new antimony (III) complexes with dithiocarbamate ligands

Eight new antimony (III) complexes containing dithiocarbamate ligands (R₂NCS₂)₂SbBr [R₂NCS₂ = OC₄H₈NCS₂ (1), C₂H₅NC₄H₈NCS₂ (2), Me₂NCS₂ (3), C₄H₈NCS₂ (4)] and (R₂NCS₂)₃Sb[R₂NCS₂ = C₅H₁₀NCS₂ (5), Bz₂NCS₂ (6), Et₂NCS₂ (7), (HOCH₂CH₂)₂NCS₂ (8)] have been synthesized by the reactions of antimony (III) halides with dithiocarbamate ligands in 1:2 or 1:3 stoichiometries. All the complexes have been characterized by elemental analysis, melting point as well as spectral [IR and NMR (¹H and ¹³C)] studies. The crystal structures of complexes 1, 5 and 8 have been determined by X-ray single crystal diffraction, and their electrochemical character has also been studied.     

1-(2′-Pyridylazo)-2-naphtholate (PAN) complexes of rhodium(III): Synthesis,structure and spectral studies

The ligating properties 1-(2′-pyridylazo)-2-naphthol (HPAN) toward Rh(III) have been examined. The reaction of RhCl₃·3H₂O with HPAN in presence of excess PPh₃ afforded trans-[Rh(PAN)Cl(PPh₃)₂]PF₆ (3PF₆). Intermediate cis-[Rh(PAN)Cl₂(PPh₃)] (4) has also been isolated. Solid state structures were authenticated by X-ray analyses revealing that monoanionic PAN is coordinated to rhodium in meridional fashion. Both the compounds were spectroscopically characterized in both solution and solid states, which include IR, NMR (¹H and ³¹P), and optical spectra. The diamagnetic complexes show multiple CT transitions in the visible region. Low-energy transitions (λ ≈ 550–650 nm) occurred in the absorption spectra are predominantly ligand centered in nature. The rhodium(III)–PAN compounds are red emissive (λ_em ≈ 650 nm) at room temperature and the nature of the emission level is probably an ILCT level. Complexes are electro-active in acetonitrile and display irreversible oxidative and reductive waves and these responses are ascribed to be PAN ligand centered in character.